In recent years, databases have been used to store more and more exotic types of information. They are no longer limited to storing alphanumeric characters or numbers (such as names, addresses, zip codes, salaries, etc.) but are also used to store, for example, images, audio files, and data formatted according to the user's own specification.
In some applications, the data stored by a database has a spatial component. For example, in addition to storing the name, address, telephone number, social security number, salary, etc. for its employees, a company may also store a spatial component—the geographic location of each employee. That information might be useful, for example, if the company is attempting to arrange training for its employees based on the location of the employees.
In some parallel processing systems, database tables are stored in partitions that are distributed among data storage facilities associated with the parallel processing system. In some of those systems, the tables including columns of spatial information may be partitioned using other non-spatial columns of the table. In those cases, efficient searching using the spatial information is a challenge.